Covert PhotoCD to Jpeg -- weird colour

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Covert PhotoCD to Jpeg -- weird colour

Postby afatac » 2009-12-10T03:35:26+00:00

I am using ImageMagick-6.5.7-Q16.

I try to convert an image from PhotoCD format[highest resolution] to Jpeg. However, the output image has very weird colour.

The command is
convert test.pcd[5] test.jpg

Converting to TIFF is OK.

Does anyone know what is happening?

A sample pcd file (BlownJohn.pcd) can be downloaded from http://tedfelix.com/PhotoCD/PCDExperiment.html
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Re: Covert PhotoCD to Jpeg -- weird colour

Postby magick » 2009-12-10T09:42:45+00:00

Add -colorspace RGB to your command line. Or use a color profile with -profile.
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Re: Covert PhotoCD to Jpeg -- weird colour

Postby afatac » 2009-12-10T09:53:39+00:00

Hi magick,

Great! It's working now. Thanks :D
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Re: Covert PhotoCD to Jpeg -- weird colour

Postby afatac » 2009-12-11T05:31:08+00:00

I notice that whenever I try to convert the highest resolution of PCD, e.g.
Code: Select all
convert -colorspace RGB BlownJohn.pcd[5] test.jpg


I get this error message
convert: Corrupt PCD image, skipping to sync byte `BlownJohn.pcd' @ pcd.c/Decode
Image/301.


However, I still can get the output jpg file and it seems OK. Converting with lower resolution (below 5) does not get the error message.

I wonder what is the error about.
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Re: Covert PhotoCD to Jpeg -- weird colour

Postby magick » 2009-12-11T07:41:09+00:00

The problem you reported is fixed in the latest release of ImageMagick, 6.5.8-4.
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Re: Covert PhotoCD to Jpeg -- weird colour

Postby afatac » 2009-12-11T22:40:08+00:00

Yes, the error message is gone. Thanks.

One new question. I came across this site regarding the lost hightlights problem in PhotoCD http://tedfelix.com/PhotoCD/PCDSoftware.html

I have tested with the latest version of ImageMagick and the result is still the same. I tried out the modified DLL supplied at that site by replacing IM_MOD_RL_pcd_.dll in coders subfolder. However, there was error occurred.

May I know how to test that modified PhotoCD DLL (or other PhotoCD DLL) in ImageMagick?
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Re: Covert PhotoCD to Jpeg -- weird colour

Postby magick » 2009-12-12T09:29:22+00:00

The article you cite is out-dated. ImageMagick handles the expanded range of Photo CD images properly. Download and convert http://tedfelix.com/PhotoCD/BlownJohn.pcd to verify:

    convert 'BlownJohn.pcd[4]' -colorspace sRGB BlownJohn.jpg
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Re: Covert PhotoCD to Jpeg -- weird colour

Postby afatac » 2009-12-12T10:01:39+00:00

Is the colorspace suppose to be RGB or sRGB? The output difference is so drastic.

Using RGB gives the blown highlights problem but it is OK for other correctly exposed images.

Using sRGB darkens and saturates the BlownJohn image. For other correctly exposed images, they become very dark.

Please let me know if you like to have another PhotoCD file for testing. I can email one to you.
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